/Engine/Source/Runtime/RenderCore/Public/ShaderPipelineCache.h
Set the current PSO Game Usage Mask and comparsion function . Returns true if this mask is different from the old mask or false if not or the cache system is disabled or if the mask feature is disabled Any new PSO's found will be logged with this value or existing PSO should have their masks updated. SeeFPipelineFileCacheManagerfor more details.
static bool SetGameUsageMaskWithComparison ( uint64 Mask, FPSOMaskComparisonFn InComparisonFnPtr )